Enhanced bioenergy recovery by innovative application of chia seeds nanopowder for anode modification in microbial fuel cell treating hospital wastewater

Microbial fuel cells (MFCs) are new bioelectrochemical techniques for conversion of organic waste materials into energy depending on the metabolic activity of the anodic biofilm, which acts as the biocatalyst in the anode compartment. Hence, the anode material is a priority for better growth of bacterial species and electrical conductivity as well. In this study, an innovative application of Chia seeds nanopowder (CSNP) was carried out for the first time with acid-activated multiwall carbon nanotubes (functionalised MWCNTs) for anode nanomodification by overlaying the surfaces of the graphite anodes (GA) in MFCs fuelled with real hospital wastewater (HWW). Two tubular-enclosed dual-chamber MFCs were constructed, setup and operated in a continuous mode for 3 months. MFC1 was assembled with CSNP/MWCNTs-GA, whereby MFC2 was assembled with MWCNTs-GA. The results revealed higher power output up to 2202.73 mW/m3 observed in MFC1 compared to 1271.57 mW/m3 in MFC2. The efficiencies of organic content (COD) removal were 86.1% and 82.9% obtained in MFC1 and MFC2, respectively. Although both efficiencies of COD removal were relatively comparable, however, a remarkable increase in COD removal efficiency was achieved in MFC1. These observations indicated the potential role of CSNP for enhancing the biofilm growth and increasing the electrode conductivity.